Steam generator



July 14', 1925. 1,545,668

' W. D. LAMONT STEAM GENERATOR Filed Dec. 28, 1918 3 Sheets-Sheet 1 w.D. LA MONT STEAM GENERATOR Filed Dec. 28, 1918 3 sheets-sheet 2 July 14,1925. I 1,545,668

Quvew'toz July 14, 1925.

w. 0. LA MONT STEAM GENERATOR Filed Dec. 28. 1918 s Sheets-Sheet a" 31mmwho: VV. 0. L afi/on f.

Quorum,

Patented July '14, N925.

' UNITED STATES PATENT oFFlca;

WALTER DOUGLAS LA MONT, OF THE UNITED STATES NAVY, ASSIGNOR, BY DIRECTAND MESNE ASSIGNMENTS, '.I.O LA MONT WASTE HEAT STEAM GENERATOR COR-IPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

STEAM GENERATOR.

Application filed December as, 1918. SerialNo. 268,651.

To all whom it may com/em:

Be it known that I, WALTER D. LA MONT, United States Navy, a citizen ofthe United States, residing at Annapolis in the county of Anne Arundel,State of Maryland, have invented certain new and useful Improvements inSteam Generators, of which the following is a description, referencebeing had to the accompanying drawings, forming a part hereof.

My invention relates to methods of and means for generating steam andhas'for its object a method of generating steam by which steam at highpressure adapted for use in steam engines may be generated quickly froma small amount of water constantly supplied so that-the weight of watercarried in the generator during the process of generating the steam willbe the least possible and will add as little as possible to the Weightof the generator itself. The invention also has for its object toprovide a steam generator adapted to carry out the method describedwhich will be simple in construction, compact and of relatively lightweight and will be adapted to effectively and safely generate steamrapidly and at high pressure from a relatively small V amount of water.

v The advantages of a steam engine for this My invention is particularlyintended for generating steam for a steam engine for use in driving thepropeller of an aeroplane.

purpose over the-explosion engine, particularly as regards possibilityof continuous operation for many hours, long life of the engine as awhole, freedom from vibration and the fatigue of the metal of the engineshaft and other parts affected by vibration, as well as otheradvantages, have long been recognized but it has not heretofore beenfound possible to produce an engine and generator, which, when inoperation, that is with water in the generator, would be sufiicientlylight in weight to be'used. The dilficulty so far as the engine itselfis concerned has been overcome,-it being possible to construct enginesof the turbine type which are sufficiently light in weight per horsepower furnished for use in an aeroplane; and the condenseralso presentsno difliculty at it is possible to design a condenser of the honeycombtype s'ufliciently light for the purpose. The serious difiiculty hasbeen in the generator. Generators which have been constructed ofrelatively light weight in themselves have been found when in use, .thatis, when supplied with the water necessary for effective operation, of aweight much too great to permit of their being used in an aeroplane.

By the use of my invention it is possible to generate steam insuflicient quantity and at sufficient pressure to effectively operatethe engine of an aeroplane without exceeding a weight, for generator andthe water contained in it during the process of generating steam, whichis well within the limit permissible for use in aeroplanes and it isalso possible to superheat the steam generatedso as to deliver it to theengine at any temperature and pressure desired.

With the above described objects and others hereinafter set forth inview, my invention consists in the method of and means forgenerating'steam hereinafter described and particularly pointed out inthe claims.

' Referring to the drawings- Figure 1 is a longitudinal verticalsectional view of a steam generator adapted to carry out my method andembodying my means section of the same on line 6-6 of Figure 5.

Figure 7 is side elevation of a portion of the spraying nozzle strip andFigure 8 is a cross-sectional view of the same in line 88 of Figure 7.

Figure 9 is a bottom plan view of a portion of the spraying nozzle stripshown in Figures 7 and 8. p

Figure 10' is a top plan view of a of the spraying nozzle strip.

Figure 11 is a side elevation of a portion portion of the lining tubefor .the distributing tube and Figure12 is a cross-section of the sameon line 12-42 of Figure 11.

It. should be understood that so far as concerns the method the drawingsare illustrative merely and are not intended to limit the inyention tothe use of the apparatus shown or to any particular form or constructionof apparatus. 7

In the drawings, 1 indicates a distributing tube at the upper end of thegenerator closed at one end and having connected to it at the other endby coupling 2 a pipe 3 leading from a header pipe 4: to which leads awater supply pipe 5 from a feed pump 6, preferably a centrifugal pump. 7indicates a collectin pipe near the lower end of the generator 0 osed atone end and connected at its other end by coupling 8 to a. pipe 9leading to a header pipe 10 fro-m which a pipe 11 leads to a separator12 for separating the steam from the water discharged from thecollecting pipe7. From this separator a pipe 13 leads upward to theengine, not shown, but preferably of the turbine type, and from thelower end of the separator a suitably valved pipe 14: leads to the pump6 to take the water separated from the steam back to the pump to beagain supplied to the distributing pipe 1.

From the distributing pipe 1 to the collecting pipe 7 extend a series ofgenerator tubes 15 suitably secured by welding or otherwise at theirends in the pipes 1 and 7. In actual construction, each of these tubesis 15 feet long, is one-half inch in exterior diameter, of seamlessdrawn steel with walls twenty-eight thousandths of an inch thick but, ofcourse, the length and diameter and other dimensions may be varied asdesired. These tubes are arranged at equal distances apart along thetubes 1 and 7, preferably so that their outer surfaces will be separated,one from the other approximately onefourth inch. In the constructionshown, there are six of the distributing tubes 1 and collecting tubes 7,each distributing tube being connected with the header pipe l and .eachcollecting tube being connected to the the header pipe 10. Forcompactness alternating distributing pipes are elevated above theintermediate ones, the same arrangement being followed with thecollecting pipes. The tubes 15 connected with one distributing pipe 1are arranged opposite the spaces between the tubes 15 connected with thenext adjacent distributing pipe.

The tubes 15 with their distributing pipes and collecting pipes areenclosed in a suitable casing 16, preferably open at the top andcorsisting of kieselguhr composition on a wire netting. This casingextends below the collecting tubes 7 to form a combustion ing tube.

usuallybe expected the weight of the gen- 1 erator in operation would betoo great to permit of its use on an aeroplane. In order to avoid thefilling of the tubes with water and thus avoid the consequent weight aswell as to secure other important advantages hereinafter more fully setforth, I provide, in accordance with my invention, for so distributingthe water in each of the tubes 15 thatit will form a thin coating orfilm on the inner surface of each tube, which will be maintained as acontinuous film from the distributing tube 1 to the collecting tube 7,or nearly to the collecting tube if it is desired to superheat the steamas hereinafter explained, so as to leave a central passage open at itslower end into which the steam generated from the film may escape as itis formed and may pass freely to the collect- By reason of the fact thatthe water is thus in a thin layer or film, steam is generated rapidlyand it is found possible to evaporate a much greater amount of water perunit of surface. per unit of time than would be possible to evaporate ifthe tubes were filled with water, and it is also possible to deliver thesteam downward without an excessive amount of water.

The steam thus generated is, of course, under pressure which ismaintained by the resistance of the turbine or other engine in which thesteam is used and as it has its outlet only from the lower end of thetube, it is necessarily maintained in the tube as a column having itsupper end towards the upper end of the tube and inthe path of the watercoming from the nozzle. As steam has, as compared with water, little orno tendency to adhere to a metal surface, this column of steam willlocate itself centrally in the tube, the water coming from the nozzle,by reason of its inherent tendency to adhere to a metal surface,clinging to the walls of the tube, filling the annular space between thecolumn of steam and these walls and forming the fihn as described, thisfilm extending downward towards the lower end .of the tube a distancedepending on the amount of water supplied and extending to the lower endof the tube if the quantity of water supplied is greater than v theamount evaporated as will ordinarily be the case.

From the foregoing description it will be noted that the method ofgenerating steam of the present invention differs essentially from thatemployed in the so-called flash boilers orgenerators in which the wateris sprayed against-highly heated surfaces in quantity only suflicient toinsure substantially instantaneous complete volatilization, thermostaticmeans being usually provided to efi'ect an automatic control of thisquantity. a

Among the advantages of the method of the present invention is that theeration of the steam from a film on the lnner wall of the tube incontra-distinction to the explosive action 'of flash generation is moreuniform and continuous and does not require the careful regulation thatis necessary with the flash boiler. Moreover, the present. invention"permits the employment of relatively thin tubes, permitting a very rapidheat exchange without danger of the tubesbeing burned out, the film ofwater protecting the tubes against this.

When the generator of the present invene tion is operated in thepreferred manner, thefilm is caused to extend substantially to the lowerend of the tube so that water and,

.steam are discharged together at this end,

. thereby avoiding any necessity for accurate control of the'water'feedwhich, as above pointed out, is requisite in flash boilers. Thegenerator of the esent invention opcrates with. a very high degree ofefiiciency under varying demands with a minimum I control of the waterfeed.

There are thus combined in this steam generator the advantage of lightWeight incidental to the'u'se of relatively small quantities of water inthe generatin tubes in the feed .to meet varying process of steamgeneration, t e advantage of protection afforded to the tubes by themamtenance of a film of water on the inside thereof during thegeneration. of the steam, and the advantage of doin away with thenecessity for careful variatlon of the Water the generator.

For the purpose of causing the water to be introduced into the tubes insuch manner as to form afilm on the interior surface of the tubes, anyconvenient form of dis tributing or spraying device which will cause thewater'to sprayed against the the device ,which I large diameter directlyabove the'tube 15 having a discharge orifice, 21 of relatively smalldiameter in line with the axis ofthe tube,in which the 'water isadmitted to the I chamber through passages 22 arranged at tangents to'the periphery of the chamber so as to cause the water as it enters thechamher to whirl or rotate and to be discharged through the orifice 21as a rotating stream throwing the water as acentrifugal spray againstthe walls of the tube. The chamber 20 is preferably formed in a solidpiece of demands made upon semicircular strip 24 and form in this loweror convex surface the tangential passages 22 as grooves leading from thepassages 23 which extend through the strip to the upper or flat face.This semicircular strip fits within a tube '25 which fits within thedistributing tube 1 and has formed in it at such intervals that when inposition each one will be in line with the axis of a tube 15, thedischarge orifices 21. 'The semicircular strip 24 is held. in positionin the tube 25 by a semicylindrical locking strip 26 or by otherconvenient means. The diameter of the chamber 20 is preferably aboutone-fourth of an inch-in diameter but may be larger.

The discharge orifice 21 is preferablyabout orifices 21 in the form of acentrifugal spray thrown outward against the walls of the tubes and"forming on these walls a thin layer or film. So long as the pressure onthe waterexceeds the pressure of steam in the tubes water will; beforced into the ends of the tubes and will form a film as described andthis film will extend as a continuous film throughout the'l'ength o fthe tube or such part of the length of .the tube as ma ,be desired,depending on the excess of te pressure on the water over the pressure ofthe steam generated. -For'ordinary purposes the pressure on thewatershould be such that the film .Will extend to the lower ends of thegenerator tubes and water and steam will be discharged together into thecollecting tubes, In a generator in which steam is to be generated at apressure of 800 pounds it is desirable to use a pressure on the water iof 200 pounds inexcess of the 800 ,pounds that is at 1000 pounds. Ifitais desired-to superheat the steam the pressure on the water isreduced so that the filni will not extend to the lower ends. of thegenerator.

tubes so that the steam generated. from the film will come in contactwith are walls of the generator tubes below the 'film and in thecollected tubes and will be superheated'by such contact.

From the collecting tubes the water and ture at which it came from thegenerator and is returned to the distributing tubes at substantiallythis temperature, thus entering the generator tubes highly heated. Ifthe steam is superheated, as above described,

there will, of course, be no water to be sep arated from the steam andthe feed pump will be supplied from the condenser.

The high pressure of the steam, in the generator tubes stiffens the tubeagainst any tendency of the tube to buckle from any unevenness ofheating. The free escape of the steam, as it is'generated through thepassage at the center of the tube, facilitates the rapid and continuousevaporation of the water and thus permits of and necessitates a veryrapid feed in order to maintain the film throughout or substantiallythroughout the length of the generator tubes. water is thus required toand does circulate rapidly incontact with the heated surfaces of thetubes, acondition which facilitates efi'ective generation.

The length of the generator tubes corresponds to the vertical distancebetween the two planes of the biplane on which it is to be used, theopen upper end of the casing 16 extending through the upper plane sothat the products of combustion will be discharged above this upperplane. The relatively great lengths of the generator tubes permits ofutilizing a very high percentage of the heat produced by the burners.

While, as above stated, the invention is particularly adaptedandin-tended for use in connection with aeroplane engines, it is obviously adapted for use in connection with steam generators for otherpurposes and may readily be adapted to any water tube type of boiler inwhich the tubes are arranged other than horizontal, that is, are soarranged that one end is substantially higher than the other so that thefilm formed on the interior of the tubes will be free to move downwardand will be aided in its movement by gravity. i

. Claims to certain separable subject matter common to this applicationand to my coplendingapplication, Serial No. 32,06 t filed ay 22, 1925,will be made in my said copending application.

Having thus described my mventionwhat I claim is:

1. The'method of generating steam, which consists in forcing water intothe upper end The of a heated tube having. one end higher than theother,*and directing the water toward the wall of said, tube, said waterbeing continuously introduced in such quantity as. continuously tomaintain a film on said wall throughout a substantial portion of thelength of the tube and to leave the center of the tube unobstructed, anddischarging from the lower end of the tube the steam am. unevaporatedwater arriving at said end.

2. The method of generating steam, which consists in continuouslyforclng Water into the upper end of a heated tube having one end higherthan the other and against the inner wall of said tube in such quantityand at such pressure in proportion to the heat of the tube as willcontinuously maintain a film on said wall substantially. throughout thelength of the tube, while leaving the center of the tube unobstructed.and discharging the steam generated from said film and the unevaporatedwater from the lower end of said tube.

3. The method of generating steam, which consists in forcing water intothe upper end of a heated tube having one end higher than the other andagainst theeinner walLotsaid tube in such quantity and at such pressurein proportionto the eat of the tube as will maintain a film on said wallsubstantially throughout the length of the tube, ,while leaving thecenter of the tube unobstructed, and dischar 'n the steam generated fromsaid film an t e unevapor-ated wat r from the lower endof said tube andseparating the steam from the water. 1

4. The method of generating steam, which consists in forcing water intothe upper end of a heated tube having one endhigher than the other andagainst the inner wall of said tube in suchquantity and at such pressurein proportion tothe' heat of the tube as will maintain a film on thesaid wall substantially throughout the length of the tube, while leavingthe center of the tube unobstructed, and discharging the steam generatedfrom said film and the unevaporated water from the lower end of saidtube, separating the steam, and returning the water end of the tube. i

5. The method of generating steam in a heated tube having one end higherthan the other, which consists in continuously forcing water into theupper end of said tube 1n a quantity eater than will be evaporated inthe tube i ut-less than suflicient to fill the tube and directin thiswater against the to the upper wall of the tube, t ereby leaving thecenter of the tube unobstructed to receive the steam generated from theformed upon the tube the steam and unevaporated .water from the lowerend of said tube.

6.'The method of generating steam in a tube of relatively great .lengthin proportion film of water thus wall, anddischarging to its diameterand having one end hi her than the other and its lower end'open, w ichconsists in heating said tube by heat-exchanging contact with heatedgases traveling up the outside of said tube throughout substantially thewhole length thereof, continuously forcing water into the upper end ofsaid tube in quantity greater than will be evaporated in said tube butless than suflicient to fill the tube, directing this water against theinner wall thereof to form a film thereon, leaving the center of thetube unobstructed to receive the steam generated from said film,continuously discharging from the lower end of said tube the steam andunevaporated water reaching said end, and separating the steam, from thewater.

7. The method of generating steam in a tube having one end higher thanthe other,

which consists in heating said tube by heatexchanging contact withheated gases traveling up the outside of said tube throughoutsubstantially the whole length thereof, continuously forcing water intothe upper end of said tube in quantity greater than will be evaporatedin said tube but less than suflicient to filll the tube, directing thiswater against the inner wall thereof to form a film thereon, leaving thecenter 'of the tube unobstructed to receive the steam generated fromsaid film, and continuously discharging steam and unevaporated waterfrom the lower end of said tube,separating the steam from the water, andreturning said water to the upper end of said tube. w I

8. In a steam generator a substantially direct generator tubesufficiently inclined to the horizontal to insure rapid gravity flow andhaving its lower end open, means for heating the tube, means forcontinuously forcing water into the upper end of said tube and sodirecting it a ainst the inner wall thereof as to form a lm thereon andleave the center of the tube unobstructed, and means for separating thewater from the mixture of steam and water discharged from. the lower endof said tube. 9. In a steam generator a substantially direct generatortube sufliciently inclined to the horizontal to insure rapid gravityflow and having its lower end open, means for heating the tube, meansfor continuously forcing water into the'-upper end of said tube and sodirecting it against the inner wall thereof as to form a fihn thereonand leave the center of the tube unobstructed, means for separating thewater from the mixture of. steam and Water discharged from the lower endof said tube. and means for conductin the separated water back to theupper end of said tube.

10. Apparatus for generating steam, comprising a series of substantiallgenerator tubes sufficiently incline to the horizontal to insure rapidgravity flow and.

direct v SllflIClGIlt to fill said tubes, means for so directing saidwater against the inner walls of said tubes as to form a film on saidwalls 'and leave the centers of the tubes unobstructed and means forseparating the water from the steam and water collected in thecollecting tube. v

11. Apparatus for generating steam, comprising a series of substantiallydirect generator tubes sufliciently inclined to the horizontal to insurerapid gravity flow and a distributing tube connected to the upper endsof said tubes, a collecting tube connected to the lower ends thereof,means for directing heated gases into. heat-exchanging contact with saidgenerator tubes throughout substantially the whole length thereof, meansfor forcin water under pressure through said distri uting tube into theupper ends of said generator tubes in quantity greater than will beevaporated to the horizontal to insure rapid gravity flow and adistributin tube connected with the upper ends of sa1d tubes, 2.collecting tube connected to the lower ends thereof,

means for directing heated gases into heatexchanging contact with saidtubes from the lower to the upper ends thereof, means for forcin waterunder pressure through said distri uting'tube into the upper ends of thegenerator tubes in quantity greater than will be evaporated in therespective tubesbut less than sui'ficient to fill them, means'for sodirectin said water against the inner walls of sai tubes as to form afilm on said walls and leave the centers of the tubes unobstructed andmeans for separating the water from the steam and water collected in thecollecting tube.

13. In a steam generator, a distributing thereof,

pared with its diameter sufliciently inclined tube, a series ofgenerator tubes communicating therewith and having their ends fastenedtherein; and a second removable tube .within said distributing tube andprovided with discharge orifices registering with the ends of saidgenerator tubes which communicate with said distributing tube.

14. In a steam generator, a complete circuit for the water thereinincluding a generating element through which the water gravitates, and aconnection between the ends of said element through which theunvaporized Water is returned to the upper end thereof, means in saidreturn connectlon for eflectlng the movement of the Water therethrough,and means also in said return connection for separating the steam fromthe mixture of steam and water issuing from the lower end of saidgenerating element.

In testimony whereof I aflix my signature this 26th day of December1918.

WALTER DOUGLAS LA MONT.

